Umut

Never becomes urgent is exactly it. The cost is designed to stay below the threshold that would make you act.

Do the arithmetic properly once, because it settles most of this and almost nobody does it.

For each category in there, write down what it would cost to replace second-hand, today, in the place you might land. Then compare that against the storage cost for however long you honestly think you will be away - and be honest, because everybody underestimates that number by about half.

When I did it the answer was stark and it was different per category:

Furniture lost badly. Generic sofas, tables, shelving - second-hand replacement was a fraction of what I was paying to store them, and that is before considering that I was paying to keep furniture I would not choose again.

Tools and the bike won easily. Expensive to replace, hold their value, and there is a real cost to rebuilding a tool collection piece by piece over years.

Books were the emotional one and lost on paper. That is a legitimate thing to pay for; it is just worth knowing that is what you are doing.

The useful outcome is not sell-or-keep, it is that you almost certainly want a much smaller unit. Most people are paying to store a small number of things they genuinely want and a large volume of things they will look at in three years and take to a charity shop. Shrinking the unit is available to you today and it does most of the saving.